Re: [Qemu-devel] [PATCH v2 0/7] ppc: compute cpu_dt_id in the machine code

[Bharata B Rao <bharata@linux.vnet.ibm.com>]

On Sat, Jul 02, 2016 at 12:41:14AM +0200, Greg Kurz wrote:
> This series is a sequel to the discussion on a patch from Ben's powernv
> patchset:
> 
>         http://patchwork.ozlabs.org/patch/597153/
> 
> Indeed, since the DT is a machine abstraction, it should definitely sit
> under hw/ppc and not in the target code:
> - all machine types are forced to share the same numbering logic
> - user mode does not need that => there are #ifdef everywhere
> 
> So this series moves all the current numbering logic to the machine
> code.
> 
> The patchset was completely re-written according to Igor's valuable
> suggestions. The main change is that cpu_dt_id is now computed out
> of a cpu_index provided by the machine, instead of bending the code
> to use cs->cpu_index.
> 
> I resend Bharata's patch without any modification because patch 6 is
> based on it (pseries-2.7 support).
> 
> I did not see any regression on pseries-2.6, pseries-2.7 and CPU hotplug.

Haven't had a chance to debug yet, but just noticed that CPU hotplug
seems to have issues after this patchset on mainline.

-smp 8,cores=1,threads=4,maxcpus=32
(qemu) device_add host-spapr-cpu-core,id=core1,core-id=16
(qemu) info cpus
* CPU #0: nip=0xc00000000007dc6c thread_id=10865
  CPU #1: nip=0xc00000000007dc6c thread_id=10866
  CPU #2: nip=0xc00000000007dc6c thread_id=10867
  CPU #3: nip=0xc00000000007dc6c thread_id=10868
  CPU #4: nip=0xc00000000007dc6c thread_id=10869
  CPU #5: nip=0xc00000000007dc6c thread_id=10870
  CPU #6: nip=0xc00000000007dc6c thread_id=10871
  CPU #7: nip=0xc00000000007dc6c thread_id=10872
  CPU #8: nip=0x0000000000000000 (halted) thread_id=10948
  CPU #9: nip=0x0000000000000000 (halted) thread_id=10949
  CPU #10: nip=0x0000000000000000 (halted) thread_id=10950
  CPU #11: nip=0x0000000000000000 (halted) thread_id=10951

[root@localhost cpus]# ls
#address-cells   ibm,drc-power-domains  name               #size-cells
ibm,drc-indexes  ibm,drc-types          PowerPC,POWER8@0
ibm,drc-names    linux,phandle          PowerPC,POWER8@10

[root@localhost cpus]# DEBUG: read_rtas_events(): Received RTAS event 1
DEBUG: handle_rtas_event(): Handling RTAS event 1
DEBUG: handle_rtas_event(): Entering check_platform_dump()
DEBUG: print_rtas_event(): Writing RTAS event 1 to /var/log/platform
DEBUG: handle_rtas_event(): Entering Hotplug handler
DEBUG: handle_hotplug_event(): Build drmgr command

DEBUG: handle_hotplug_event(): run: drmgr -c cpu -a -s 0x10000010 (null)

DEBUG: handle_hotplug_event(): Invoke drmgr command

Validating CPU DLPAR capability...yes.
Requested CPU with drc index 10000010 is already present.
DEBUG: handle_hotplug_event(): drmgr call exited with 1

If instead of core-id=16, if I use core-id=24, then hotplug succeeds but
the CPU gets unexpected dt_id(0x30) as shown below:

(qemu) device_add host-spapr-cpu-core,id=core2,core-id=24

[root@localhost cpus]# ls
#address-cells   ibm,drc-power-domains  name               #size-cells
ibm,drc-indexes  ibm,drc-types          PowerPC,POWER8@0
ibm,drc-names    linux,phandle          PowerPC,POWER8@10

[root@localhost cpus]# DEBUG: read_rtas_events(): Received RTAS event 1
DEBUG: handle_rtas_event(): Handling RTAS event 1
DEBUG: handle_rtas_event(): Entering check_platform_dump()
DEBUG: print_rtas_event(): Writing RTAS event 1 to /var/log/platform
DEBUG: handle_rtas_event(): Entering Hotplug handler
DEBUG: handle_hotplug_event(): Build drmgr command

DEBUG: handle_hotplug_event(): run: drmgr -c cpu -a -s 0x10000018 (null)

DEBUG: handle_hotplug_event(): Invoke drmgr command

Validating CPU DLPAR capability...yes.
Could not retrieve ibm,ppc-interrupt-server#s property for 
CPU 24
Rotating logs...
DEBUG: handle_hotplug_event(): drmgr call exited with 0

DEBUG: process_v6(): Processing version 6 event
DEBUG: report_menugoal(): menugoal: number = 651301, message = "Platform
Firmware Not applicable."
DEBUG: (Sequence #1) servicelog key 96.

[root@localhost cpus]# ls
#address-cells   ibm,drc-power-domains  name               PowerPC,POWER8@30
ibm,drc-indexes  ibm,drc-types          PowerPC,POWER8@0   #size-cells
ibm,drc-names    linux,phandle          PowerPC,POWER8@10